Bug 191858 - [msdosfs] [panic] Disposed page 0xfffff807d41eeb60 is dirty
Summary: [msdosfs] [panic] Disposed page 0xfffff807d41eeb60 is dirty
Status: Closed FIXED
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: i386 Any
: --- Affects Only Me
Assignee: freebsd-fs (Nobody)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-07-14 09:08 UTC by Peter Holm
Modified: 2018-05-17 16:16 UTC (History)
2 users (show)

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Description Peter Holm freebsd_committer freebsd_triage 2014-07-14 09:08:31 UTC 
On FreeBSD 11.0-CURRENT #1 r268601: Mon Jul 14 08:59:23 CEST 2014
    pho@x4.osted.lan:/usr/src/sys/i386/compile/PHO i386

Create a large number of small files on a

mdconfig -a -t swap -s 3g -u $mdstart
bsdlabel -w md${mdstart} auto
newfs_msdos -F 32 -b 8192 /dev/md${mdstart}a

and delete them.

Details @ http://people.freebsd.org/~pho/stress/log/msdos5.txt
Comment 1 Mark Linimon freebsd_committer freebsd_triage 2014-07-20 18:05:53 UTC 
over to maintainers.
Comment 2 Vladyslav Movchan 2018-05-17 09:03:25 UTC 
I suppose this problem (panic: Freeing unused sector) might be caused by the same reason described in bug 213507.
I.e. in directories with the large amount of files (directories which occupy more than one cluster) garbage-like directory entries could appear.
Attempt to interpret such dentries (which are basically random data) could lead to unexpected results.

Could you please try to reproduce this on CURRENT after base r333693?
To reproduce this problem myself I tried to create several hundreds of directories with 500 to 1000 small files in each and removing them all at once.
I repeated this procedure multiple times but was not able to trigger this on r333698.
Comment 3 Peter Holm freebsd_committer freebsd_triage 2018-05-17 11:43:14 UTC 
I repeated the test on r333704 and did not find any problems.
Comment 4 Kirk McKusick freebsd_committer freebsd_triage 2018-05-17 16:16:10 UTC 
This problem was resolved with revision: 333693.

https://svnweb.freebsd.org/changeset/base/333693